From patchwork Mon Mar 16 15:00:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrey Smirnov X-Patchwork-Id: 197982 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCDD2C0044D for ; Mon, 16 Mar 2020 15:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CFC32071C for ; Mon, 16 Mar 2020 15:01:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JbwYli8P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731773AbgCPPBL (ORCPT ); Mon, 16 Mar 2020 11:01:11 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:44229 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731754AbgCPPBL (ORCPT ); Mon, 16 Mar 2020 11:01:11 -0400 Received: by mail-pg1-f195.google.com with SMTP id 37so9894068pgm.11; Mon, 16 Mar 2020 08:01:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=MPrOSWSrtPAEMOuF4bEaFRsvrmYiw/O9v/DoKWrsQLE=; b=JbwYli8PzqFdYTJQePcHzbahKJtd0nkhWDma1aA1fH0s7FG0EotH22QWY+b7U/h5tc fCsDswcX2eyeqW1a+EKf9GoCwJ5Dlt5cUaXAkpuk75KAv/cOPK2n/8UcWZEpQyIftkzF MmcPS44qbOdoRKyLZUMgH/LuBTJGnw+wvXyQWqNHPGCnOgAH6Rx41laMicA3E0A0PjWj bp9FXm6ReTlUAkY5DaSihVwF3PrB4XYcyjpVxVUYDhm0Km0zrqZB0StrXi7ct/NFplkL /kug/f9ZfRAkS3SJ+v2cb1afjXQYuXZpHZW46728yfKcCaRreyPYrW9vQc3LLW3DklXt m3hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MPrOSWSrtPAEMOuF4bEaFRsvrmYiw/O9v/DoKWrsQLE=; b=f9mq185VL8jhM2GXFBBFhmjppSeGl6HUXHjtGLYlVxMLjaJNkbP1rG3AzAyaiafln6 N+K58zx7fWXKmZbRfrloTs8jRwWRCOgi4MXrqHw5mzxkhtaUjiPoaHPGlWH/SjdMuUtH AYsQ/BfXfec0x4c9hjb7WRheEPwO3wbvU+R8g/UlrfRUgWW67sU8x7JC9Q1sPbgF1Iui LUl/Qb2lpHKNz5+51CPnCtm5YCkMbEOnbpmkPwmC4Eblo/W9brqdea9pHRHLabLhdMkk PI3LpEHBC23oXmCOFR7HpfCAcyrTQw0dG7pV0ULy1qDFlaQTgVXQQeHSUDBVTI3braw5 WNlg== X-Gm-Message-State: ANhLgQ0VBbfvDNrhjhNioAUQ0ZR4OGDjeT+VaL6ucI/KL2DPu//rmx2Q oh1/eVtTTsTQp/9Ksb3VNtwJa7uc X-Google-Smtp-Source: ADFU+vtdgycAdmnsDPdTKhjsHfcdNXjwrsCQYDikc4md2en4GNEbUYiiO7lwxRQnYYlMmyq3Xh5ZLw== X-Received: by 2002:aa7:9250:: with SMTP id 16mr10562pfp.205.1584370868842; Mon, 16 Mar 2020 08:01:08 -0700 (PDT) Received: from localhost.localdomain (c-67-165-113-11.hsd1.wa.comcast.net. [67.165.113.11]) by smtp.gmail.com with ESMTPSA id o128sm256354pfg.5.2020.03.16.08.01.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Mar 2020 08:01:07 -0700 (PDT) From: Andrey Smirnov To: linux-crypto@vger.kernel.org Cc: Andrey Smirnov , Chris Healy , Lucas Stach , =?utf-8?q?Horia_Geant?= =?utf-8?b?xIM=?= , Herbert Xu , Iuliana Prodan , linux-kernel@vger.kernel.org, linux-imx@nxp.com Subject: [PATCH v8 4/8] crypto: caam - simplify RNG implementation Date: Mon, 16 Mar 2020 08:00:43 -0700 Message-Id: <20200316150047.30828-5-andrew.smirnov@gmail.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200316150047.30828-1-andrew.smirnov@gmail.com> References: <20200316150047.30828-1-andrew.smirnov@gmail.com> MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Rework CAAM RNG implementation as follows: - Make use of the fact that HWRNG supports partial reads and will handle such cases gracefully by removing recursion in caam_read() - Convert blocking caam_read() codepath to do a single blocking job read directly into requested buffer, bypassing any intermediary buffers - Convert async caam_read() codepath into a simple single reader/single writer FIFO use-case, thus simplifying concurrency handling and delegating buffer read/write position management to KFIFO subsystem. - Leverage the same low level RNG data extraction code for both async and blocking caam_read() scenarios, get rid of the shared job descriptor and make non-shared one as a simple as possible (just HEADER + ALGORITHM OPERATION + FIFO STORE) - Split private context from DMA related memory, so that the former could be allocated without GFP_DMA. NOTE: On its face value this commit decreased throughput numbers reported by dd if=/dev/hwrng of=/dev/null bs=1 count=100K [iflag=nonblock] by about 15%, however commits that enable prediction resistance and limit JR total size impact the performance so much and move the bottleneck such as to make this regression irrelevant. NOTE: On the bright side, this commit reduces RNG in kernel DMA buffer memory usage from 2 x RN_BUF_SIZE (~256K) to 32K. Signed-off-by: Andrey Smirnov Cc: Chris Healy Cc: Lucas Stach Cc: Horia Geantă Cc: Herbert Xu Cc: Iuliana Prodan Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-imx@nxp.com --- drivers/crypto/caam/caamrng.c | 323 ++++++++++++---------------------- 1 file changed, 108 insertions(+), 215 deletions(-) diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c index 753625f2b2c0..b3b92e5944cd 100644 --- a/drivers/crypto/caam/caamrng.c +++ b/drivers/crypto/caam/caamrng.c @@ -7,35 +7,12 @@ * * Based on caamalg.c crypto API driver. * - * relationship between job descriptors to shared descriptors: - * - * --------------- -------------- - * | JobDesc #0 |-------------------->| ShareDesc | - * | *(buffer 0) | |------------->| (generate) | - * --------------- | | (move) | - * | | (store) | - * --------------- | -------------- - * | JobDesc #1 |------| - * | *(buffer 1) | - * --------------- - * - * A job desc looks like this: - * - * --------------------- - * | Header | - * | ShareDesc Pointer | - * | SEQ_OUT_PTR | - * | (output buffer) | - * --------------------- - * - * The SharedDesc never changes, and each job descriptor points to one of two - * buffers for each device, from which the data will be copied into the - * requested destination */ #include #include #include +#include #include "compat.h" @@ -45,38 +22,26 @@ #include "jr.h" #include "error.h" +#define CAAM_RNG_MAX_FIFO_STORE_SIZE U16_MAX + +#define CAAM_RNG_FIFO_LEN SZ_32K /* Must be a multiple of 2 */ + /* - * Maximum buffer size: maximum number of random, cache-aligned bytes that - * will be generated and moved to seq out ptr (extlen not allowed) + * Length of used descriptors, see caam_init_desc() */ -#define RN_BUF_SIZE (0xffff / L1_CACHE_BYTES * \ - L1_CACHE_BYTES) - -/* length of descriptors */ -#define DESC_JOB_O_LEN (CAAM_CMD_SZ * 2 + CAAM_PTR_SZ_MAX * 2) -#define DESC_RNG_LEN (3 * CAAM_CMD_SZ) - -/* Buffer, its dma address and lock */ -struct buf_data { - u8 buf[RN_BUF_SIZE] ____cacheline_aligned; - dma_addr_t addr; - struct completion filled; - u32 hw_desc[DESC_JOB_O_LEN]; -#define BUF_NOT_EMPTY 0 -#define BUF_EMPTY 1 -#define BUF_PENDING 2 /* Empty, but with job pending --don't submit another */ - atomic_t empty; -}; +#define CAAM_RNG_DESC_LEN (CAAM_CMD_SZ + \ + CAAM_CMD_SZ + \ + CAAM_CMD_SZ + CAAM_PTR_SZ_MAX) /* rng per-device context */ struct caam_rng_ctx { struct hwrng rng; struct device *jrdev; - dma_addr_t sh_desc_dma; - u32 sh_desc[DESC_RNG_LEN]; - unsigned int cur_buf_idx; - int current_buf; - struct buf_data bufs[2]; + struct device *ctrldev; + void *desc_async; + void *desc_sync; + struct work_struct worker; + struct kfifo fifo; }; static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r) @@ -84,228 +49,153 @@ static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r) return (struct caam_rng_ctx *)r->priv; } -static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd) +static void caam_rng_done(struct device *jrdev, u32 *desc, u32 err, + void *context) { - if (bd->addr) - dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE, - DMA_FROM_DEVICE); -} - -static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx) -{ - struct device *jrdev = ctx->jrdev; - - if (ctx->sh_desc_dma) - dma_unmap_single(jrdev, ctx->sh_desc_dma, - desc_bytes(ctx->sh_desc), DMA_TO_DEVICE); - rng_unmap_buf(jrdev, &ctx->bufs[0]); - rng_unmap_buf(jrdev, &ctx->bufs[1]); -} - -static void rng_done(struct device *jrdev, u32 *desc, u32 err, void *context) -{ - struct buf_data *bd; - - bd = container_of(desc, struct buf_data, hw_desc[0]); + struct completion *done = context; if (err) caam_jr_strstatus(jrdev, err); - atomic_set(&bd->empty, BUF_NOT_EMPTY); - complete(&bd->filled); - - /* Buffer refilled, invalidate cache */ - dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE); - - print_hex_dump_debug("rng refreshed buf@: ", DUMP_PREFIX_ADDRESS, 16, 4, - bd->buf, RN_BUF_SIZE, 1); + complete(done); } -static inline int submit_job(struct caam_rng_ctx *ctx, int to_current) +static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma, int len) { - struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)]; - struct device *jrdev = ctx->jrdev; - u32 *desc = bd->hw_desc; - int err; + init_job_desc(desc, 0); /* + 1 cmd_sz */ + /* Generate random bytes: + 1 cmd_sz */ + append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG); + /* Store bytes: + 1 cmd_sz + caam_ptr_sz */ + append_fifo_store(desc, dst_dma, len, FIFOST_TYPE_RNGSTORE); - dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf)); - init_completion(&bd->filled); - err = caam_jr_enqueue(jrdev, desc, rng_done, ctx); - if (err != -EINPROGRESS) - complete(&bd->filled); /* don't wait on failed job*/ - else - atomic_inc(&bd->empty); /* note if pending */ + print_hex_dump_debug("rng job desc@: ", DUMP_PREFIX_ADDRESS, + 16, 4, desc, desc_bytes(desc), 1); - return err; + return desc; } -static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait) +static int caam_rng_read_one(struct device *jrdev, + void *dst, int len, + void *desc, + struct completion *done) { - struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng); - struct buf_data *bd = &ctx->bufs[ctx->current_buf]; - int next_buf_idx, copied_idx; + dma_addr_t dst_dma; int err; - if (atomic_read(&bd->empty)) { - /* try to submit job if there wasn't one */ - if (atomic_read(&bd->empty) == BUF_EMPTY) { - err = submit_job(ctx, 1); - /* if can't submit job, can't even wait */ - if (err != -EINPROGRESS) - return 0; - } - /* no immediate data, so exit if not waiting */ - if (!wait) - return 0; - - /* waiting for pending job */ - if (atomic_read(&bd->empty)) - wait_for_completion(&bd->filled); - } - - next_buf_idx = ctx->cur_buf_idx + max; - dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n", - __func__, ctx->current_buf, ctx->cur_buf_idx); + len = min_t(int, len, CAAM_RNG_MAX_FIFO_STORE_SIZE); - /* if enough data in current buffer */ - if (next_buf_idx < RN_BUF_SIZE) { - memcpy(data, bd->buf + ctx->cur_buf_idx, max); - ctx->cur_buf_idx = next_buf_idx; - return max; + dst_dma = dma_map_single(jrdev, dst, len, DMA_FROM_DEVICE); + if (dma_mapping_error(jrdev, dst_dma)) { + dev_err(jrdev, "unable to map destination memory\n"); + return -ENOMEM; } - /* else, copy what's left... */ - copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx; - memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx); - ctx->cur_buf_idx = 0; - atomic_set(&bd->empty, BUF_EMPTY); - - /* ...refill... */ - submit_job(ctx, 1); + init_completion(done); + err = caam_jr_enqueue(jrdev, + caam_init_desc(desc, dst_dma, len), + caam_rng_done, done); + if (err == -EINPROGRESS) { + wait_for_completion(done); + err = 0; + } - /* and use next buffer */ - ctx->current_buf = !ctx->current_buf; - dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf); + dma_unmap_single(jrdev, dst_dma, len, DMA_FROM_DEVICE); - /* since there already is some data read, don't wait */ - return copied_idx + caam_read(rng, data + copied_idx, - max - copied_idx, false); + return err ?: len; } -static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx) +static void caam_rng_fill_async(struct caam_rng_ctx *ctx) { - struct device *jrdev = ctx->jrdev; - u32 *desc = ctx->sh_desc; - - init_sh_desc(desc, HDR_SHARE_SERIAL); - - /* Generate random bytes */ - append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG); - - /* Store bytes */ - append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE); - - ctx->sh_desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc), - DMA_TO_DEVICE); - if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) { - dev_err(jrdev, "unable to map shared descriptor\n"); - return -ENOMEM; - } - - print_hex_dump_debug("rng shdesc@: ", DUMP_PREFIX_ADDRESS, 16, 4, - desc, desc_bytes(desc), 1); + struct scatterlist sg[1]; + struct completion done; + int len, nents; + + sg_init_table(sg, ARRAY_SIZE(sg)); + nents = kfifo_dma_in_prepare(&ctx->fifo, sg, ARRAY_SIZE(sg), + CAAM_RNG_FIFO_LEN); + if (!nents) + return; + + len = caam_rng_read_one(ctx->jrdev, sg_virt(&sg[0]), + sg[0].length, + ctx->desc_async, + &done); + if (len < 0) + return; + + kfifo_dma_in_finish(&ctx->fifo, len); +} - return 0; +static void caam_rng_worker(struct work_struct *work) +{ + struct caam_rng_ctx *ctx = container_of(work, struct caam_rng_ctx, + worker); + caam_rng_fill_async(ctx); } -static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id) +static int caam_read(struct hwrng *rng, void *dst, size_t max, bool wait) { - struct device *jrdev = ctx->jrdev; - struct buf_data *bd = &ctx->bufs[buf_id]; - u32 *desc = bd->hw_desc; - int sh_len = desc_len(ctx->sh_desc); + struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng); + int out; - init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER | - HDR_REVERSE); + if (wait) { + struct completion done; - bd->addr = dma_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE); - if (dma_mapping_error(jrdev, bd->addr)) { - dev_err(jrdev, "unable to map dst\n"); - return -ENOMEM; + return caam_rng_read_one(ctx->jrdev, dst, max, + ctx->desc_sync, &done); } - append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0); + out = kfifo_out(&ctx->fifo, dst, max); + if (kfifo_len(&ctx->fifo) <= CAAM_RNG_FIFO_LEN / 2) + schedule_work(&ctx->worker); - print_hex_dump_debug("rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4, - desc, desc_bytes(desc), 1); - - return 0; + return out; } static void caam_cleanup(struct hwrng *rng) { struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng); - int i; - struct buf_data *bd; - for (i = 0; i < 2; i++) { - bd = &ctx->bufs[i]; - if (atomic_read(&bd->empty) == BUF_PENDING) - wait_for_completion(&bd->filled); - } - - rng_unmap_ctx(ctx); + flush_work(&ctx->worker); caam_jr_free(ctx->jrdev); + kfifo_free(&ctx->fifo); } -static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id) +static int caam_init(struct hwrng *rng) { - struct buf_data *bd = &ctx->bufs[buf_id]; + struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng); int err; - err = rng_create_job_desc(ctx, buf_id); - if (err) - return err; + ctx->desc_sync = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN, + GFP_DMA | GFP_KERNEL); + if (!ctx->desc_sync) + return -ENOMEM; - atomic_set(&bd->empty, BUF_EMPTY); - submit_job(ctx, buf_id == ctx->current_buf); - wait_for_completion(&bd->filled); + ctx->desc_async = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN, + GFP_DMA | GFP_KERNEL); + if (!ctx->desc_async) + return -ENOMEM; - return 0; -} + if (kfifo_alloc(&ctx->fifo, CAAM_RNG_FIFO_LEN, GFP_DMA | GFP_KERNEL)) + return -ENOMEM; -static int caam_init(struct hwrng *rng) -{ - struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng); - int err; + INIT_WORK(&ctx->worker, caam_rng_worker); ctx->jrdev = caam_jr_alloc(); err = PTR_ERR_OR_ZERO(ctx->jrdev); if (err) { + kfifo_free(&ctx->fifo); pr_err("Job Ring Device allocation for transform failed\n"); return err; } - err = rng_create_sh_desc(ctx); - if (err) - goto free_jrdev; - - ctx->current_buf = 0; - ctx->cur_buf_idx = 0; - - err = caam_init_buf(ctx, 0); - if (err) - goto free_jrdev; - - err = caam_init_buf(ctx, 1); - if (err) - goto free_jrdev; + /* + * Fill async buffer to have early randomness data for + * hw_random + */ + caam_rng_fill_async(ctx); return 0; - -free_jrdev: - caam_jr_free(ctx->jrdev); - return err; } int caam_rng_init(struct device *ctrldev); @@ -335,15 +225,18 @@ int caam_rng_init(struct device *ctrldev) if (!devres_open_group(ctrldev, caam_rng_init, GFP_KERNEL)) return -ENOMEM; - ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_DMA | GFP_KERNEL); + ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; + ctx->ctrldev = ctrldev; + ctx->rng.name = "rng-caam"; ctx->rng.init = caam_init; ctx->rng.cleanup = caam_cleanup; ctx->rng.read = caam_read; ctx->rng.priv = (unsigned long)ctx; + ctx->rng.quality = 1024; dev_info(ctrldev, "registering rng-caam\n");